Set the default value of BookTheme to auto?

[leoheitmannruiz]

Hey!!

I feel like BookTheme being set to auto is the default value most people expect, though, of course, I might be wrong.

What do you think about this?

[alex-shpak]

Hi!
I'm not sure here, I kept it in light just as default and having the same view, same expectation, my gut feel is just to keep it that way

[leoheitmannruiz]

With no further implications intended beyond simple curiosity: what do you think is the default value most people expect?

I don't have much else to say here :)

Feel free to close this issue and the PR #594